A mobile phone provided with a camera and a digital still camera each using a solid-state imaging device such as a CCD and a CMOS are known. In such imaging units, further reduction in size has been desired, and in a lens for shooting to be mounted thereon, further reduction in size and reduction in total length have been desired.
Moreover, recently, in a small imaging unit such as a mobile phone provided with a camera, both reduction in size and an increase in the number of pixels have been achieved, and a model including an imaging device having a large number of pixels, for example, having ten million pixels or more has been widely used. Accordingly, an imaging lens having high lens performance corresponding to such a solid-state imaging unit having a large number of pixels has been desired.
Meanwhile, in the imaging unit, a bright lens with a larger aperture has been desired in order to prevent a decrease in sensitivity of the imaging device and an increase in noise that are accompanied by reduction in cell pitch. An imaging lens having a five-lens configuration is currently mainstream as such a small high-performance imaging lens, and, for example, image lenses described in Patent Literatures 1 and 2 are known.